Penile length preservation after prosthesis: is Ams Lgx more effective than Ams Cx? A prospectic, randomized study

Enrico Caraceni1, lilia Utizi1, Luca Leone2, Edoardo Pescatori3
  • 1 Ospedale di Civitanova Marche, U.O. Urologia (Civitanova Marche)
  • 2 Università Politecnica delle Marche (Ancona)
  • 3 Hesperia Hospital (Modena)


Hydraulic penile prosthesis implantation (PPI) is almost unanimously considered the best solution for severe erectile dysfunction (ED); while patients and their partners commonly report high quality of life scores and satisfaction rates, a potential issue is postoperative reduced penile length. To verify if the AMS LGX prosthesis, with cylinders expanding in girth and length, can prevent penile shortening following surgery, and to compare its impact on penile length with the AMS CX device, which cylinders expand in girth only (1).

Materials and Methods

Thirty-two consecutive patients with severe ED scheduled for three-component hydraulic penile prosthesis placement were randomized in two groups: AMS LGX and AMS CX devices. Preoperatively a baseline stretched penile length (SPL) was obtained. In both groups our routine strategy for length preservation, consisting of cylinder oversizing (1 cm) and device kept activated for two weeks postoperatively, was used. Post-operatively penis length at fully inflated device was recorded at 1, 6 and 12 months. Participants completed the ”Quality of Life and Sexuality with Penile Prosthesis” (QoLSPP) questionnaire at one year follow-up.(2-3)


Baseline mean SPL were: 14.7 cm (range:12.5 – 17) in the LGX group; 15.4 cm (range:12.5 – 17.5) in the CX group. At 1 month postoperatively no difference emerged between the two device groups in terms of fully inflated device penile length compared to baseline measurements. At 6 months follow-up the LGX group showed a mean significant length increase of 0.9 cm (p=0.008) compared to baseline, while the CX group did not (p= 0.556). At 1 year follow-up both LGX and CX groups exhibited a statistically significant mean increase in penile length compared to baseline (2.1 cm, p=0.001, and 0.8 cm, p=0.001, respectively). QoLSPP questionnaire showed high scores in all its domains (functional, relational, social and personal) in both groups, with no significant differences emerging between the two groups. (4)


Both tested devices, with strategies of cylinder oversizing and prolonged postoperative activation, prevent penile shortening, promote penile length gain, and are associated with high satisfaction rates and QoL scores.


The LGX device provides a greater and faster penile length gain compared to the CX device. The 20% LGX cylinder in vitro length gain indicated by the Company translates in a in vivo penile length gain of 14.3% at one year follow-up.


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2. Montorsi F, Rigatti P, Carmignani G, Corbu C, Campo B, Ordesi G, Breda G, Silvestre P, Giammusso B., Morgia G, Graziottin A. AMS three-piece inflatable implants for erectile dysfunction: a long-term multi-institutional study in 200 consecutive patients. Eur Urol 2000;37:50–5
3. Caraceni E, Utizi L. A questionnaire for the evaluation of quality of life after penile prosthesis implant: quality of life and sexuality with penile prosthesis (QoLSPP): to what extent does the implant affect the patient's life? J Sex Med. 2014 Apr;11(4):1005-12
4. Caraceni E, Utizi L, Angelozzi G. Pseudo-capsule “coffin effect”: how to prevent penile retraction after implant of three-piece inflatable prosthesis. Arch Ital Urol Androl 2014; 86(2): 135-137